1. Field of the Invention
The present invention relates generally to portable electronic devices which utilize batteries. More particularly, the present invention relates to portable medical devices. Still more particularly, the present invention relates to methods and apparatus for the maintenance and management of the batteries of such portable medical devices.
2. Description of the Prior Art
Battery management is a concern in any portable electronic device, but is a primary concern in portable medical devices. The need for more comprehensive battery maintenance in portable and implantable medical devices has been noted, for example, in U.S. Pat. No. 4,080,558 to Sullivan, U.S. Pat. No. 5,411,537 to Munshi, et. al., U.S. Pat. No. 5,483,165 to Cameron, et. al., and U.S. Pat. No. 5,470,343 to Fincke, et. al.
A defibrillator is a device capable of delivering a preset amount of electrical energy to a patient's heart for the purpose of terminating an arrhythmia. For portable defibrillators, batteries are used to provide the electrical energy delivered. Historically, portable defibrillator maintenance has been problematic due to insufficient means to ensure comprehensive management of the batteries. As portable medical devices are intended for relatively long-term monitoring and, in the case of portable defibrillators, intended for therapeutic shock delivery for patients at risk from sudden cardiac death due to tachyarrhythmias, a comprehensive battery management program is essential.
Historically portable defibrillator design has been concerned with ensuring that the devices function properly when needed. Problems may arise if the batteries of the defibrillators are at less than full capacity or are worn out or are accidentally taken off their chargers so that the batteries are nonfunctional.
Therefore, there is a need in the portable electronic device industry, and, in particular, in the portable medical electronic device industry to implement a comprehensive way of informing the patient, as precisely as possible, of the status of that patient's device, and particularly the status of the device battery. This status should include not only the current conditions of the device battery but also other information, such as an indication of how much time remained in which the device would be operable.